JPS59173528A - Electronically controlled fuel injection pump - Google Patents

Abstract

PURPOSE:To improve a cold start performance, by providing an electric means in an electromagnetic actuator for adjusting a position of a fuel control member so as to heat the electromagnetic actuator, and thereby controlling electrical connection in response to preheating operation of glow plugs. CONSTITUTION:When a key switch 8 is turned on to start a Diesel engine, current is supplied to an auxiliary starting device 9, and a preheating circuit 10 is operated for only a fixed time Ta as set by a timer incorporated in the auxiliary starting device 9. As a result, a rapid preheating current is supplied to glow plugs 21-24. On the other hand, a level of an output wire 9a is maintained at H for the fixed time Ta, and an output of an AND gate 14 in a switch control circuit 13 is also maintained at H to close a switch 12. Accordingly, a heating element 11 incorporated in an electromagnetic actuator 5 starts a heating operation. Thereafter, when the switch 8 is selected to a ST position, the output of the AND gate 14 is changed through an inverter 15 to L, and the switch 12 is opened to stop the heating operation of the heating element 11.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electronically controlled fuel injection pump.

The electromagnetic actuator connected to the fuel adjustment member of the fuel injection pump for a diesel engine is driven and controlled in accordance with a control signal output in response to an electric signal indicating the operating conditions of the engine. Many electronically controlled fuel injection pumps have been proposed in the past, which control the injection amount in accordance with the operating conditions of the actuator. As the viscosity increases significantly at low temperatures, the traction of the stain magnetic actuator increases, which eliminates the problem of being unable to start the engine at low temperatures. In other words, at low temperatures, the viscosity of the lubricating oil inside the electromagnetic actuator increases, which reduces the operating speed of the electromagnetic actuator and causes a large response delay. Unfortunately, this is detected as a servo error in the control system, resulting in a no-injection state and making it impossible to start the engine. In addition, since the battery capacity decreases at low temperatures, the starting power cannot be increased sufficiently, resulting in poor starting performance.Even if the engine starts, if the key switch is turned off for some reason immediately after starting, the
Due to the increase in viscosity inside the magnetic actuator, the fuel adjustment unit does not return to the no-injection position quickly, which not only delays engine stopping but also poses the risk of the engine going into overdrive condition. Ta.

In order to solve the above-mentioned problem of the engine not being able to start due to a delay in the response of the electromagnetic actuator during starting, it is possible to start the engine by ignoring the servo error in the control system that occurs during starting. Although it is conceivable to configure the control system so that the control system operates, it has the disadvantage that it may cause an overrun if a servo error actually occurs in the control system.

Therefore, it is an object of the present invention to provide an electronically controlled fuel injection pump that eliminates the above-mentioned 7 reactions that occur in the electromagnetic actuator at low temperatures and does not interfere with the starting operation at low temperatures.

A feature of the configuration of the present invention for achieving the above object is that, in an electronically controlled fuel injection pump for a diesel engine equipped with an electromagnetic actuator for adjusting the position of a fuel adjustment member, a glow plug installed in a diesel engine is provided. In response to the preheating operation of the electromagnetic actuator, a heating current is supplied to the electric means for heating the electromagnetic actuator. The means for heating the electromagnetic actuator may be a heater element separately provided within the actuator, or a solenoid coil of the electromagnetic actuator may be used. According to this configuration, the viscosity of the lubricating oil in the electromagnetic actuator can be lowered by using the preheating time of each cylinder of the diesel engine, so that the engine can be started without any problem at low temperatures. can.

Hereinafter, the present invention will be explained in detail with reference to the illustrated embodiments.

The drawing shows an example of a diesel engine device to which an electronically controlled fuel injection pump according to the present invention is applied. In the drawings, the reference numeral 1 indicates a glow plug;
A 4-cylinder diesel engine with 21 to 24 cylinders,
The configuration is such that fuel is injected and supplied to each cylinder of the diesel engine 1 from a series of electronically controlled fuel injection pumps 3 connected to the diesel engine 1.

A control rack 4, which is a fuel adjustment member provided in the fuel injection pump 3, is connected to an electromagnetic actuator 5 via an appropriate means such as a link mechanism. The electromagnetic actuator 5 is connected to a control circuit 7 to which an electric signal S1 indicating the operating conditions of the diesel engine 1 is input from the operating condition detector 6, and is outputted from the control circuit 7 in response to the electric signal S. The drive is controlled according to the drive signal engineer.
As a result, positioning control of the control rack 4 is performed so that an optimum injection amount matching the operating conditions of the diesel engine 1 can be obtained.

On the other hand, for the purpose of preheating control of the glow plugs 2□ to 24, a starting assist device 9 is provided which operates in response to the switching operation of the key switch 8.
When the potential of the ON position negative contact 8a of the key switch 8 becomes the same level as the power supply voltage +V by switching from the F position to the ON position, the preheating circuit 10 is activated and a rapid preheating current is applied to the glow plugs 21 to 24. The glow plugs 21 to 24 are preheated by flowing for a certain period of time Ta.

The above-mentioned rapid preheating operation period T& is determined by a timer circuit (not shown) built into the starting aid device 9, and the level of the output line 9a of the starting aid device 9 is set only during the rapid preheating operation period. It becomes rHJ.

In order to eliminate the above-mentioned operational failure of the electromagnetic actuator that occurs at low temperatures, a heater element 11 is provided in the electromagnetic actuator 5. One end of the heater element 11 is grounded, and the other end is connected via a switch 12. is connected to the power supply +V. The switch 12 is controlled to open and close by a switch control circuit 13 that operates in response to a change in the level of the output line 9a of the starting assist device 9 and the operation of the key switch 8.

The switch control circuit 13 has a two-way switch 14, one input terminal of which is connected to the output 9&, and the other input terminal connected to the contact 8b of the key switch 8 in the ST position. It is connected to the output terminal of the connected inverter 15. The input terminal of the inverter 15 is also grounded via the resistor 16, so that when the key switch 8 is in the OFF or ON position, the level of the output terminal of the inverter 15 is RHJ, and the key switch 8 is in the OFF or ON position. When switch 8 is in the ST position, inverter 15
The level of the output terminal of is rLJ.

According to this configuration, when the key switch 8 is in the OFF position, the level of the output terminal of the inverter 15 is "H".
However, since the level of the output line 9a is rLJ, the output level of the AND/DART 14 is rLJ, and the switch 12 is in an open state. Key switch 8 is O
When switched to the N position, as described above, the output lfE! 9
Since the level of 1L becomes rHJ for a predetermined time Ta, the output level of AND gate 14 also becomes rHJ in response to switching of key switch 8 to the ON position, and switch 12 is closed. That is, the key switch 8 is turned on from the OFF position.
Heating of the heater element 11 is started at the same time as the rapid preheating operation is started, and heating of the heater element 11 is continued until the rapid preheating operation is completed.

However, when the switch 8 is switched from the ON position to the ST position during the rapid preheating operation, the level of the input terminal of the inverter 15 becomes rLJ, so the switch 12 is opened and heating of the heater element 11 is stopped.

According to the switch control circuit 13, as described above, the stain magnetic actuator 5 can be heated by the heater element 11 during the rapid preheating operation period, so that the temperature inside the electromagnetic actuator 5 is reduced before cranking at low temperatures. The viscosity of lubricating oil can be reduced to a level that does not interfere with starting operations.

In the above embodiment, a heater element 11 for heating is separately provided in the electromagnetic actuator 5, or a current is passed through the lenoid coil 5& of the electromagnetic actuator 5 via the switch 12, thereby heating the stain magnetic actuator 5. It may be configured to heat without the heater element 11. According to such a configuration, since the conventional electromagnetic actuator can be used as is, there is no need to use a special tit actuator and only a simple energization control circuit is added, which is extremely economical.

Further, in the above embodiment, an embodiment using a size-shaped fuel injection pump was described, but it is easily understood from the above description that the present invention is not limited to this. .

Furthermore, in the above embodiment, the energization control of the heater element 11 is performed by the switch control circuit 1 configured by a dart circuit.
3 shows the case where a small amount of execution is performed, but it goes without saying that it is also possible to control by program processing using a microcomputer. In this case, it is also possible to execute the energization control program for the heater cord 11 using another control circuit, for example, a microcomputer used in the control circuit 7.

According to the present invention, as described above, since the electromagnetic actuator is heated using the preheating time of the glow plug, even at low temperatures, the viscosity of the lubricating oil in the electromagnetic actuator is reduced until the preheating of the glow plug is completed. Until then,
It can be made sufficiently low to the extent that it does not interfere with the starting operation, and the low-temperature starting characteristics can be significantly improved compared to the conventional one.

[Brief explanation of the drawing]

The drawing is a block diagram showing the configuration of an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Diesel engine 1,21 to 24... Glow plug, 3... Fuel injection pump, 4... Control rack, 5... Electromagnetic actuator, 6... Operating condition detector, 7... ...Control circuit, 8...Key switch,
9... Starting aid device, 11... Heating heater element,
12... Switch, 13... Switch control circuit. Patent applicant: Diesel Equipment Co., Ltd.

Claims (1)

[Claims] 1. The electromagnetic actuator that adjusts the position of the fuel adjustment member is driven and controlled in accordance with a control signal output in response to an electric signal indicating the operating conditions of the internal combustion engine, and the fuel is adjusted in accordance with the operating conditions of the internal combustion engine. An electronically controlled fuel injection pump adapted to be connected to an internal combustion engine for injection, further comprising an electric means for heating the electromagnetic actuator, and in response to a preheating operation of a glow plug installed in the internal combustion engine. Electronically controlled fuel injection pump, characterized in that it supplies heating current to electrical means.